Saturday, 17 October 2020

Who measured what? the case of the two inch overhang

Week Ending 17 October 

Monday, it's Dave and Nigel dodging the rain while cutting vegetation on the Gretton to Prescott Road stretch. Starting at Working Lane with Culvert 25A then moving along to the south. Only a couple of questionable bits, the first was with the H5 that Roger carved in the new path at Winchcombe, Dave looked at it upside down so he couldn't work out the cryptic message 😉 

Photo's from Dave  

Culvert 25A up side outfall 

Outlet stream from Culvert 25B 

Culvert 25A outlet ditch 

Culvert 25B up side headwall


The plan for 2020 was to rebuild the culverts 24A, B and C, then move on to stick a new headwall on 25B. It's another long overdue job. While all this work was going to happen, contractors would have done a lot of work reshaping the outlet from Culvert 25A to shore up the side of Working Lane. Alas none of this has happened, but one thing that has happened, thanks to our downstream neighbour is that the outlet ditch has been dug out. 


Culvert 25B outlet stream 

Culvert 25B down side 

Next move was to skip up to 27B on the other side of Gretton. 

Culvert 27B down side headwall 

Culvert 27B down side inlet area 
Another site that needs an extensive rebuild 

Culvert 27B up side headwall 

Culvert 27B downstream runs through a garden 

Culvert 31B up side, another site in need of work 


By Thursday another job had dropped in that need a rapid response, so Andrew and Martin went up to Stanton to Bridge 8. It was a report of a broken lid on the cess channel next to the high mileage wing wall on the up side of the bridge. The grass had grown over the channel and the lids aren't visible, hence the rapid response to make the site safe. 

Report from Andrew 

Bridge 8 HM up side wing wall  
Drain hidden under the grass 

Up side concrete channel cess drain 

Up side cess channel drain 

Up side cess concrete channel 

Offset bracing in the concrete channel sections  

Chamber on the end of the channel 

Site made safe until a permanent solution can be implemented 

Next door to Bridge 8 is Culvert 7A, this is a siphon under the track. There's a leak on the up side headwall that needed to be checked while the culvert was cleared of vegetation. 

Culvert 7A down stream rather overgrown 

GRP lid left over the excavation behind the outlet headwall 

Culvert 7A down side inlet chamber 


Disappointing start to Friday morning, the last batch of 1.8m concrete lids were removed from the moulds in the lean-to and ferried around to the pile. While loading them onto the pallet it was discovered that 2 of the lids had cracked. This could have been wile removing them form the moulds or stresses applied during the loading and unloading operations. Not all is lost though, a repair may be possible or they can be cut down for the 900mm stock. 

12 x 1.8m Concrete lids manufactured 

Even after a week drying in the mould 
the lids managed to crack 

After that, it was down to Bridge 29 to remove the broken end coping stone to bring back to Winchcombe to work out to build up a substitute. On the way in at Working Lane a new landscape feature was noticed... 


3 loads of spent ballast have appeared next to Culvert 24C 

A stop off at Bridge 25 to measure the end coping stones prove to be enlightening, there' not 16"x16", they're 16"x18" so are these correct measurements for Bridge 29?  

Bridge 25 end coping stone, no overhang 

Sure enough, measuring the good coping on Bridge 29 showed that it was in fact a 16"x18", so where had the 16"x16" come from. 

End coping
on Bridge 29 down side abutment 

Broken end coping on Bridge 29, there's an overhang of 2" 

After a bit of scrabbling around the missing bit was uncovered 

Roger removes the coping stone 

The abutment wall is only 14" wide  

Bridge 29 is another puzzler, why use 16" coping stones with a 2" overhang on the outside, was this a BR or early GWSR repair job or has it been like that from new. We have a stock of 14" copings, so could in theory take the lot off and put the correct width on. 

Tidying up the mortar ready for a replacement 

The end coping on the down side wing wall needs reseating 

The up side abutment on Bridge 29 has been rebuilt, this looks like an early GWSR job as it used brick pillars and scaffold poles. Shame it can't be used to compare with the other side.  

Bridge 29 up side abutment 

There's a chamber in Dixton that is need on some 900mm lids, so our cracked lid may find a new home 

Dixton up side chamber with broken lid 

Next stop was Kayte Lane, Culvert 41C to pump out the siphon to check what size it is. On the way over Pecked Lane crossing there was an abandoned wheelie bin on the track. Luckily the lid still had last year's Green Bin chit stuck on so you didn't have to be Inspector Morse to work out where it came from. Needless to say, the bin got returned to its owner, whether they wanted it back or not. 

Abandoned full bin, or was it just a schoolboy prank 

There's some desperate folks in Cleeve, they've even broken through the palisade fence to get in...  

Is it break in or a break out 

Culvert 41C is a twin bore siphon that runs diagonally under Kayte Lane crossing, the idea today was to expose one of the pipes to see what it was. 

Kayte Lane Occupation Crossing 

Culvert 41C inlet 

3" pump brought out of hibernation to drain the inlet end 

Soon down by 2 course of bricks 

Water pumped out into the down side cess, giving it a flush 

The pump worked well and soon had the flow under control 

8 courses (32") down and still no pipe 

Pipe exposed 9 courses down, it's an 18" spun iron 

That's a load of water pumped out 

Over on the outlet end the pipe never appeared 

Large silt build up on the outlet 

To pump out one pipe, the water had to drain from both pipes until it stopped running round at the outlet end and back into pipe that was being pumped. The silt at the outlet acted as dam and made the job a bit easier. But, the silt in the inlet meant that it never got much below the top of the pipe before air broke the suction  

Culvert 41C outlet ends 

Culvert 41C down side inlet ends 

The downstream ditch here is an a shocking state, the flow is badly restricted by willow roots 

Culvert 41C downstream 

Willow roots in the stream 

Not sure what's happened to this willow 

A public footpath runs across the crossing,
used by runners quite a bit 

Within 15 mins of the pump being shut down the water level was back to within a brick of where it was 

Culvert 41C outlet end 

Culvert 41C inlet end 

On the way back out tracks were spotted at Bridge 41, the abandoned bridge. A peek in showed some fresh beer cans, there mustn't be anything exciting to do in Cleeve if this is the best they can find.  

Bridge 41 can recycling centre  

Up side entrance to Bridge 41 

So back at Winchcombe Roger put the jigsaw together and and it looks like a matching repair can be made by cutting 2 broken bits (another good end was uncovered down the up side embankment). That'll be for next week if things go to plan 

How many bits does it take to make a fresh end coping stone 


3 comments:

  1. Very interesting blog, and the 'to do' end coper looks like it will be a n exciting job when completed.
    Regards, Paul.

    ReplyDelete
  2. You guys do a very big and important job for the GWSR. Well done.

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  3. Mike Slipper is quite right, I am full of admiration for this team and work they do, thanks for this. I spend Tuesday a.m. in hospital running tests, so it was good to be home and have this to take my mind off blood samples etc!

    ReplyDelete